Passive keyless entry (PKE) is an automotive security system that operates automatically when the user of a vehicle is in proximity to the vehicle, unlocking the door on approach or when the door handle is pulled and locking it when the user walks away or touches the car on exit. The vehicle may also be started by the user when the PKE system is detected inside of the vehicle. PKE systems may also be used to secure buildings or areas of buildings.
PKE System for car access rely on wireless technology for the communication between the vehicle and the key device (Key device can be a key-fob, a smartphone or any other portable radio enabled device).
Remote keyless entry (RKE) is an electronic access system that can be controlled from a distance. RKEs, which are typically used to remotely lock or unlock doors, require the end user to initiate an action that will cause a physical or software key fob to transmit a radio signal to a receiver that controls an electronic lock. Typically, the action is to press a button on a physical fob or mobile app.
Traditional key fob uses low frequency communication with the associated vehicle and operations can be performed through a key fob if it is determined, via received signal strength, that the key fob is in a close proximity to the vehicle. However, it is not difficult to use a relay attack to make it appear that the key fob is in close proximity even though it is not.